Hydraulic mooring winch



Dec. 15, 1964 H. SANDOY 3,

HYDRAULIC MOORING WINCH Filed Dec. 26, 1961 5 Sheets-Sheet 2 INVENTOR:

HARRY SANDUY.

Dec. 15, 1964 H. SANDOY 3, 61,

HYDRAULIC MOORING WINCH Filed Dec. 26. 1961 5 Sheets-Sheet 5 INVENTORZ HARRY SA NDQY.

Dec. 15, 1964 H. SANDCJY 3, 6 ,0

HYDRAULIC MOORING WINCH Filed Dec. 26. 1961 5 Sheets-Sheet 4 NV TOR:

HARRY SA @Y.

Dec; 15, 1964 H. sANDOY 3,161,022

HYDRAULIC IMOORING WINCH Filed Dec. 26. 1961 5 Sheets-Sheet 5 FIGS 57 INVENTOR:

HARRY SANDZY.

United States Patent Claims. ion. 60-53) This invention relates to a hydraulic winch adapted for use in mooring.

It has been previously proposed in such winches to lead the mooring line or hawser over an arrangement which measures the tension in the line and which by means of a servomechanism causes the winch to haul in line when the tension decreases and to pay out line when the tension increases. This has appeared, however, to be not very suitably. Firstly, it is preferred to use one and the same winch for various fairleads which in that case would necessitate the use of a separate arrangement for each fairlead. Secondly, it has been found that the winch cannot be made to react quickly enough. A third disadvantage is that such winches can only be used with diificulty as cargo winches, that is as loading and unloading winches.

The object of the invention is to avoid the aforementioned disadvantages and to provide a winch the hydraulic system of which is modified so that a constant tension in the mooring line is maintained.

According to the present invention, a hydraulic mooring winch comprises a pump, a hydraulic motor for operating a winch drum and coupled in a hydraulic circuit in series with the pump, a manually operable control valve for regulating the quantity of fluid fed to the motor from the pump by bypassing an adjustable portion of the amount of liquid in the pump in a short circuit outside the hydraulic motor, an overflow valve comprising an overflow passage which leads from the pressure side of the installation to its discharge side in parallel with the motor and the control of which being dependent upon the pressure differential between these sides so that the pressure of the pressure side is maintained essentially constant, and means for adjusting this pressure so that it corresponds to the desired tension in the mooring line.

In the previously proposed hydraulic winches as are mentioned preliminarily it is also known to have several speed steps, which are connected and disconnected egg. by means of automatically operating change-over valves responsive to the pressure in the system. In practice this is carried out such that the motor and/or pump contain more than one chamber having separate supply or feed, and that this or these extra chambers can be changed over to idling. 'When the winch is to be rearranged for mooring, it must, however, often be adjusted to a load below the highest loading level. This means in that case that the hydraulic fluid, which is normally oil, is circulated at a relatively high pressure. This can lead to undesirable heating of the oil.

A further object of the invention is, therefore, to remedy this disadvantage of a hydraulic system of this type.

This is attained by the winch comprising means for setting the said change-over valve or valves out of operation in the mooring position and to maintain a low speed level, largely independent or What pressure difference the by-pass valve is set at.

In order that the invention may be more clearly understood one particular embodiment thereof will now be described, by way of example, with reference to the accompanying drawings in which:

FIGURE 1 shows, largely diagrammatically, the hydraulic system of a winch according to the invention.

FIGURE 2 shows, partly simplified, two vertical sections through a pump which is used in the invention, in which the section A shows a section in a first radial plane and section B in another radial plane.

FIGURE 3 shows a vertical section through the control valve. I

FIGURE 4- shows a vertical section'through an auxiliary valve which is included in the hydraulic driving system, together with the associated part of the motor.

FIGURE 5 shows a vertical section through another auxiliary valve which is included in the winch according to the invention, and

FIGURE 6 shows a plan of the auxiliary valve shown in FIGURE 5. 1

In apparatus shown in FIGURE 1, there is shown in dotted lines a hydraulic auxiliary control system which is utilized in the embodiment of the invention for converting a winch (not shown) from operating as a mooring winch to operating as a cargo winch and vice versa.

The winch is driven by two separate pumps 10 and 11 which supply pressure oil to feed conduits 12 and 13 respectively. The pump 10 is protected by a safety valve 14, while the pump 11 communicates with a change-over valve 15 which will be described later. In line 13 downstream of this change-over valve 15 there is located a check valve 16, the two feed conduits 12 and 13 joining at a point 17 downstream of the check valve 16, and continuing from there as a common feed conduit 18.

As is shown in FIGURE 2 the two pumps 10, 11 with .the associated parts 12-17 are housed within a common housing 19 from which only the common feed conduit 18 extends. Return or discharge fluid is introduced through a common discharge conduit 20.

The feed conduit 18 leads to, and the discharge conduit 29 comes from, a manually operable control valve 21 with a slide member 22. This control valve is of a construction which in practice is identical to that which is described in US. Pats. 2,736,170 and 2,822,668. The mode of operation of this valve is considered known to those skilled in the art.

The slide member 22 of control valve 21 is adjusted for hoisting (FIG. 1) with parallel feed to two motor circuits 23, 24 while vtwo other motor circuits 2'5, 26

are controlled by each of their change-over valves 27, 28. These last-mentioned are of the type which are described in US. Pat. 3,013,577 with the modification that the central bore through the body of the valve is replaced by a separate supply to the lower end of the valve housing, as will be explained later.

In practice the motor circuits 23, 24 and 25 consist of the individual chambers in a hydraulic vane motor with three chambers, while motor circuit 25 is constituted by a separate motor which is secured at the opposite side of the winch drum and which is constituted by a hydraulic three-chamber motor Whose chambers are charged in parallel with driving oil.

As is known, the winch can be adjusted so that only the feed conduit 29 of motor circuit 23 is charged with driving oil under pressure, while the motor circuit 24 is disconnected and short-circuited in the manner which is described in Norwegian Patent No. 73,443 and motor circuits 25, 26 are charged with discharge oil from a common discharge conduit 30. All this is, as mentioned, described in the aforementioned US. Patents 2,736,170 and 2,822,668.

However, extending from the feed conduit 29 to the discharge conduit 30 is a branch conduit 31 in which a special by-pass valve 32 is located. This by-pass valve is of known construction and is such that it can be set to open at a predetermined pressure and thereafter to maintain this pressure in question in the system.

During normal use of the winch as a cargo winch, valve 32 is set to a sufficiently high opening pressure, which is higher than the pressure of the safety valve, so that it will not open. Then the winch will act as a normfl loading and unloading winch of the kind which is described in Patents 2,736,170 and 2,822,668.

For use as a mooring winch, however, the winch is set at a position for hauling with both motor circuits 23 and 24 charged from the control valve 21, and the valve 32 set to open at a definite pressure difierence between lines 29 and 30, and thereby to allow precisely enough oil to pass to maintain this difference. This means that the radial vanes in the hydraulic motor are subjected to a predetermined pressure and hence impart a torque to the winch drum (not shown), which in turn creates a hauling-in force of a definite magnitude to the line (not shown) which is coiled up on the drum.

If the ship is moored to a side of a lock while the lock is being filled, the ship will be pulled against the lock side with a precisely adjusted force. If the filling of the lock necessitates shortening of the mooring lines, the winch will automatically take care of this. The same applies when the ship is moored to a quay side.

It will be apparent that this operation is due to the circulating through the valve 32 of a quantity of oil supplied by the pump above a pressure of a definite magnitude. This means in efiect a loss of power which is equal to the quantity of oil circulated multiplied by the pressure used.

In order to keep this loss of power as low as possible, in this embodiment of the invention, the quantity of fluid supplied by the pump is reduced by keeping only one pump cell active in the mooring position, and secondly the predetermined pressure is brought as low as possible. The latter is achieved by rendering the automatic control of motor circuits 25 and 26 inactive, whereby both these motor circuits remain active, irrespective of the level of the predetermined pressure.

In order to etfect this adjustment, an auxiliary hydraulic system is used which acts upon the ditferent valves. This auxiliary system is controlled by a valve denoted by reference numeral 33.

Valve 33 comprises (see FIGURE a slide 35 displaceably mounted in a valve housing 34. The slide comprises a hollow portion which is open at its lower end, while an opening 36 at its upper end ensures that communication is maintained between the spaces below the lower end and above the upper end respectively of the hollow portion. At the lower end the slide carries a flange 37 controlling a port or opening 38 in the wall, so that this opening is either connected to another opening 39 higher up the bore of the valve housing, or connected to the opening at the lower end of the hollow portion. Above the opening 39 a first and second flange 40 and 41 are arranged which by pulling the slide up into the upper position, are able to close an opening 42 in the wall of the bore. In the lower position of the slide, however, the opening 42 is in communication with an opening 43 just a little higher up in the bore,

while a flange 44 shuts otf communication with the upper end of the bore. Above this latter flange there is a wide upper opening 45, arranged at the upper end of the bore.

The slide is actuated by a stem 46 which extends outside the housing and which is connected to manual adjusting means which will be referred to later.

The lower opening 38 is connected by a conduit 47 to the two change-over valves 27, 28 and, moreover, in such a way that the conduit 47 replaces the central bore through the valve member of Patent 3,013,577. The opening 39 is charged with pressure oil through a conduit 48 which is connected to the feed conduit 29 of the motor circuit 23. The opening 42 is charged with pressure oil from the supply conduit 18 from the pump via a conduit 49, while the opening 43 is connected by a conduit 50 to the change-over valve 15 of the second pump. The upper opening 45 is connected to the main discharge conduit 30 by means of a conduit 51.

The slide 35 can as stated be moved to a lower position wherein the openings 38 and 39 are communicating, and the openings 42 and 43 are in communication with each other, while the upper opening 45 is isolated by the flange 44. Then, in a well known way, the position of the two change-over valves will be dependent upon the pressure in the feed conduit of the motor circuit 23, and the second pump will be active and will feed drive fluid to the control valve in parallel with the first pump. This will consequently be the position for use of the winch as a cargo winch.

The slide 35, however, can also be moved to an upper position wherein the discharge oil is fed from the upper opening 45 to the lower opening 38 through the space in the hollow portion of the slide. Such discharge oil is also fed in this position to the opening 43, while the openings 39 and 42 are shut 01f from communication with the other openings. This will cause discharge oil to be fed to the lower side of the valve members of the change-over valves 27, 28, and likewise to the rear side of the second pumps change-over valve 15. This will mean that the change-over valves 27 and 28 will be changed over to feed drive fluid to the motor circuits 25, 26, while the second pump is arranged to idle. This, in other words, is the position of the slide 35 when the winch is used as a mooring winch.

The external shape of the bypass valve 32 is shown in FIGURE 5. The top of this terminates in an axially movable pin 52 which by downward pressure will subject the control spring (not shown) of the valve to higher compression. This means that the pressure needed for opening the by-pass valve is increased.

To the upper end of the pin 52 is linked one end of a link member 53, which at its other end is linked at 54 to the upper side of the valve housing 55 which houses the various additional valves (see FIGURE 5). The link member 53 slopes slightly upwards from the point of linkage 54 to the pin 52, and against its upper side acts a roller 56 which is secured to the lower side of a movable indication piece 57. This indication piece is movably engaged on guides 58 so that on being moved from the right towards the left in FIGURE 5 it will press the link member 53 steadily more downwards. The indication piece is provided with a scale which is divided into tons and indicates the tension in the mooring line which the winch is thereby adjusted to.

On the lower side of the link member 53 there is a bracket 59 with a slotshaped cut out portion, which retains a pin 60 secured on an axle 61. On this axle is similarly secured a pivotable arm 62 which, by means of a link connection generally designated by 63, is connected with the stem 46 which actuates the adjustable slide 35. On the end of the axle 61 which extends outside the housing 55 there is fitted an adjusting handle 64 (FIGURE 6). When the adjusting handle is located in the lower position as shown, the slide 35 of the link system 63 and associated stem 46 will be moved to its lowermost position. As has been mentioned, this means that the winch will then act as a normal cargo winch. Similarly, the pin 60 acts against the bracket 59 and pulls the link member 53 downwards; this will cause the control spring of the by-pass valve 32 to be compressed so strongly that the by-pass valve will not open at the pressure which normally prevails in the system. (If this is desired one can regulate the degree of compression, that is, the cooperation between the pin 61 and the bracket 59, so that the bypass valve opens at a definite excess pressure, and thereby operates as an additional safety valve which prevents overloading in the motor. The pres-sure should be appreciably higher than the highest normal working pressure of the winch.)

The adjusting handle 64 can also be raised to an upper position, and in this position it is locked together with the controller handle when this is located in the hoisting position in the position where both the motor circuit 23 and motor circuit 24 are charged with oil. This locking together takes place by moving a pin (not shown) at the, end of an arm secured to the shaft of the control handle into a slot in the adjusting handle 64.

When the adjusting handle is located in this position, the slide 35 of the link system 63 will be pulled up to its upper position, at the same time as the pin 6% releases the bracket 59. The indication piece 57 can then be moved to a position which adjusts the control spring in the valve 32 to the desired bypass pressure.

The rearrangement of this slide 35 to its upper position causes the discharge oil to be fed to the valves 27 and 28 so that the motor circuits 25 and 26 are also charged with drive fluid, just as the valve 15 is readjusted so that the pump 11 is put out of operation.

All the motor circuits are now charged with pressure fluid at a definite excess pressure, for example of kg./cm. This produces a tension in the hoisting line of corresponding magnitude, which is dependent on the total area of the vanes, and the rotor diameters in the motors together with the diameter of the line drum. The valve 32 will maintain the tension by allowing more oil through if the tension should increase and by allowing less oil through when the tension decreases. This reaction will take place almost immediately, depending upon the reaction time of the valve 32. This reaction time is naturally chosen as low as possible.

In the foregoing description it is assumed that the different valves used, that is the control valve 21, the changeover valves 27, 28 and the by-pass valve 32, are of the kind which are described in the various prior patents oi the patentee. There is, however, nothing to prevent these valve being replaced by others which will operate and react in a corresponding manner.

An important feature of the winch when it concerns installation on a ship where it is desired to employ sev oral mooring winches which are to be used alternatively, is that all the fluid from the pump is tied to the control valve of the winch and back to the pump through a single circuit. By the expression all the fluid from the pump in this connection is meant the amount of fluid which the pump supplies at a given moment. As is well known, this will be half of the pumps maximum capacity in the mooring position, and the whole of the pumps maximum capacity in the cargo position. This feature means namely that two or more such winches can be coupled in series and fed from a single pump. This takes place, therefore, in a manner such that the discharge conduit Zn from the one winch leads oil to the next winch to constitute the feed conduit 18 for the next winch.

Ther'etore, when one winch is in use the fluid circulates through a short circuit in the control valve to the other winch.

Provided the combined load on the winches does not exceed the maximum loading capacity of the pump, both winches can be used at the same time by such a series coupling, for example, by using the one as a mooring 6 winch, while'the other is used as a cargo winch'for lighter loads. In this case, the latter will only be able to hoist at half speed and to lift comparatively light loads, but it can still be used, as has been mentioned, without influencing the operation of the mooring winch.

Also the invention can be varied in many other ways without departing from the spirit of the invention as is defined in the following claims.

What I claim is: i

1. A hydraulic system for a mooring winch, said system having pressure and discharge sides and comprising a pump, a hydraulic motor including vanes adapted for operating a winch drum and coupled in a hydraulic circuit in series with said pump, a manually operable control valve for regulating the quantity of fluid fed to said motor from said pump by directing an adjustable portion of the amount of liquid from said pump in a short circuit around said motor back to said pump, a bypass valve having a bypass passage which leads from said pressure side of said system to said discharge side of said system and connected in parallel with said motor, said bypass valve including means responsive to the pressure difference between said sides for maintaining the pressure on said pressure side of said system substantially at a constant value above the pressure on discharge side of said system and means for adjusting the pressure difference so that the resulting torque by said pressure acting towards the vanes of said motor will be maintained at a substantially constant value.

2. A system according to claim 1, wherein the hydraulic system is adjustable to operate at'several speed levels by the assistance of means including automatically operable changeover valves which react to the pressure in the system and including means for selectively putting the change-over means out of operation and to maintain a low speed level, independent of the pressure to which said bypass valve is adjusted.

3. A hydraulic system for a mooring winch comprising a pump, a hydraulic motor having radial vanes arranged on a rotor enclosed in a motor housing, a first conduit for pressure fluid leading from the pump to the motor to direct pressure fluid towards one side of said vanes, a second conduit for discharge fluid leading from the motor back to the pump to discharge fluid from the opposite side of said vanes and to lead such fluid back to the pump, a manually operable control valve inter-' posed in said conduits between said motor and said pump, said manually operable control valve being adjustable to a first position in which said first conduit is brought to communicate with said second conduit by a throttled opening, and to a second position in which said first and second conduits are isolated from each other, a by-pass conduit leading from said first conduit to said second conduit, a bypass valve arranged in said bypass conduit, means for setting said by-pass valve to open and allow all pressure fluid to flow through said by-pass conduit when the pressure in said first conduit exceeds a predetermined value and to close and isolate said first and second conduits from each other when the pressure in said first conduit drops below said predetermined value, and means for allowing said by-pass valve to be set for such openin only when said manually operable control valve is in its second position.

4. A hydraulic system for a mooring winch according to claim 3 wherein the hydraulic motor comprises at'least two motor circuits which are charged with pressure fluid by parallel supply conduits, a changeover valve being arranged in one of said supply conduits and having a first position in which said supply conduit of the corresponding motor circuit is closed oif from said first conduit for pressure fluid and a second position in which said supply conduit is open, further comprising means for bringing said change-over valve to assume its second position as soon as the by-pass valve is set for opening at said predetermined value.

5. A hydraulic system for a mooring winch according to claim 4, wherein said means for bringing the changeover valve to assume its second position is a valve having a first position in which pressure fluid is charged to a control chamber of said change-over valve and a second position in which discharge fluid is charged to said control chamber, said valve being moved to its second position as soon as the means for setting the by-pass valve is moved to set the valve and to its first position as soon as such setting means are made inoperative.

References Cited by the Examiner UNITED STATES PATENTS 2,736,170 2/56 Huse 60-53 HARRISON R. MOSELEY, JULIUS E. WEST,

Examiners. 

1. A HYDRAULIC SYSTEM FOR A MOORING WINCH, SAID SYSTEM HAVING PRESSURE AND DISCHARGE SIDES AND COMPRISING A PUMP, A HYDRAULIC MOTOR INCLUDING VANES ADAPTED FOR OPERATING A WINCH DRUM AND COUPLED IN A HYDRAULIC CIRCUIT IN SERIES WITH SAID PUMP, A MANUALLY OPERABLE CONTROL VALVE FOR REGULATING THE QUANTITY OF FLUID FED TO SAID MOTOR FROM SAID PUMP BY DIRECTING AN ADJUSTABLE PORTION OF THE AMOUNT OF LIQUID FROM SAID PUMP IN A SHORT CIRCUIT AROUND SAID MOTOR BACK TO SAID PUMP, A BYPASS VALVE HAVING A BY-PASS PASSAGE WHICH LEADS FROM SAID PRESSURE SIDE OF SAID SYSTEM TO SAID DISCHARGE SIDE OF SAID SYSTEM 